1. Field of the Invention
This invention relates to an all terrain vehicle (ATV) and vehicles especially adapted for snow and for other terrains in which standard tires are ineffectual, such as mud. And more particularly, this invention relates to a conversion system to convert an the standard tires of ATV for use in snow and such other terrains in which the standard tires are ineffectual.
2. Background Information
An ATV is a three or four wheel vehicle similar to a motorcycle for use in rugged terrain such as mountains and other areas. This type of vehicle is functional in the Summer, but for the most part, is not very useful in the Winter, particularly when it snows, or on other terrains in which standard tires are ineffectual. This puts a seasonal limitation on an ATV.
During the Winter season, in areas where snow covers the ground, people resort to a vehicle known as a snowmobile. These vehicles have tracks, as opposed to wheels, which are better for running in snow. However, the expense of owning both an ATV and a snowmobile is for many, prohibitive. However, the seasonal limitations on these vehicles means that in some areas, both will be needed.
When the owner of an ATV resides in an area where Winter is severe, an ATV is difficult, if not impossible to use. Even an ATV with special tires is not practical or safe for use in snow and ice. For that reason, the ATV is invariably stored during the Winter months and replaced with a snowmobile.
Additionally, in areas in which the terrain makes driving with standard tires difficult, such as mud and similar surfaces, the ATV is largely ineffectual, and other modes of transportation must be adopted.
To solve this problem, attempts have been made to convert an ATV for use in snow, or for other terrains, but to-date, no practical system has been successful. One method is to provide wrap-around snow treads. Another method is to replace the stock tires with snow tires. Neither of these methods provide a machine that is very good in snow. They do not work at all well or as advertised, and are too complicated or too expensive for practical use. It would be advantageous if a system could be provided that is as simple as possible to convert an ATV for use in snow, and then be able to easily reconvert it back for use on dirt. It would also be advantageous to be able to do this at an expense that would be a substantial savings over having two separate vehicles.
An object of the present invention is to provide an ATV conversion system that permits conversion of an ATV into an all season vehicle. Yet another object of the present invention is to provide an ATV conversion system that allows the vehicle to be easily converted for use in snow, and other terrains in which standard tires are ineffectual, and converted back easily to standard wheels and tires for use on dirt. It is also an object of the present invention to provide an ATV conversion system that is as simple as possible. Yet another object of the present invention is to provide an ATV conversion system that makes it equally simple to convert the vehicle back for use with conventional tires. Still another object of the present invention is to provide a snow conversion system that permits conversion of an ATV by removal of the wheels and installing cog-driven dual rear tracks, and replace the front wheel or wheels with skis. Yet another object of the present invention is to provide an ATV conversion system that includes a drive axle designed for use with both cog-driven tracks and standard ATV wheels. Yet another object of the present invention is to provide an ATV conversion system, including an adjustable torsion bar to provide proper weight transfer.
Yet another object of the present invention is to provide an ATV conversion system having a wide drive cog for receiving snow tracks that provide optimum power transfer. Still another object of the present invention is to provide an ATV conversion system having drive cogs and a wheel replacement system that includes track tension adjustment. Yet another object of the present invention is to provide an ATV conversion system with a drive cog and snow tracks that include a double slide rail for optimal weight distribution. Yet another object of the present invention is to provide an ATV conversion system having a drive cog and snow tracks that includes a track guide alignment system. Still another object of the present invention is to provide an ATV conversion system having a ski assembly for replacing the front wheel or wheels that includes a brake retention mount.
Prior art has addressed various methods of attaching tracks to wheeled vehicles. U.S. Pat. No. 3,860,080 discloses apparatus for mounting and endless track on the tire of the vehicle without removal of the tire. The apparatus includes means for tightening the track around the upper periphery of the tire, and means, attached to the bumper and frame of the vehicle, for limiting the rotation of the apparatus. Such apparatus is inadequate in several ways: 1) the track is only in frictional contact with the wheel, enabling the wheel to rotate within the track when the friction on the bottom surface of the track exceeds the friction between the wheel and the track; and 2) the means for limiting the rotation of the apparatus is a pair of chains which, under appropriate circumstances, can damage either the bumper of the vehicle, or the apparatus, or both.
U.S. Pat. No. 3,939,930 embodies the same concepts as the '080 patent above in that the limiting device on rotation of the track apparatus is a chain attached to the bumper of the vehicle, and suffers the same shortcomings. In contrast to the '080 patent, the '930 patent discloses a sprocket which replaces the tire of the vehicle, the teeth of which sprocket extend outwardly to then mesh with apertures in the track in order to propel the track.
U.S. Pat. No. 4,448,273 discloses an apparatus for replacing the wheels of a vehicle with an endless track assembly. The apparatus included a sprocket for receiving cogs manufactured on the inner surface of the track. The sprocket is attached directly to the hub of the vehicle axle by means of a flange at one end of a shaft on which the sprocket is mounted. This apparatus is inadequate in that the sprocket is sufficiently narrow that any sideways displacement of the track will result in the track becoming displaced from the sprocket. In addition, there are no idler wheels on the outside portion of the track to maintain the track in optimum contact with the terrain. And lastly, the apparatus does not have any means of restricting the undesired rotation of the apparatus, or to bias the apparatus in an attitude conducive to traversing uneven terrain.
The assembly of the invention addresses the problems noted above by providing a easy to mount conversion system which requires no modification to the standard ATV. The drive sprocket of the track extends the width of the track, providing a larger footprint for the ATV, and the assembly includes a means for biasing the track that does not pose the opportunity for damage to the ATV.